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First Thoughts: Debate No. 9

GOP debate No. 9 takes place in Michigan beginning at 8:00 pm ET, and it comes just one day after Cain’s defiant press conference… What else to watch for at the debate… And Perry’s up with a new TV ad in Iowa.

ROCHESTER, MI -- Tonight's Republican presidential debate here -- the ninth of the cycle and the first one since Oct. 18 -- couldn't have come at a more fitting time. It's the first debate since the sexual-harassment allegations against Herman Cain first surfaced. It's the first debate since the contentious Mitt Romney-vs.-Rick Perry showdown in Las Vegas. And it’s the first debate to come after a fresh round of worries about European debt and European economic instability. Also, it’s the first debate of the cycle to take place in the Industrial Midwest. Indeed, Michigan has an 11.1% unemployment rate, it’s lost thousands of manufacturing jobs in the past decade, and it has the fourth-highest foreclosure rate in the country.

*** What to watch for: The debate, of course, comes just a day after Cain’s press conference in Arizona, where he defiantly denied the sexual-harassment charges against him. “They simply didn’t happen,” he said. His defiance is one of the reasons why his supporters like him so much. But that kind of defense will only work if the ENTIRE truth is on his side, because he now has put himself in the position where he is daring his accusers to come out with more evidence. And, voila, a second accuser is no freely speaking to the media. As far as how these allegations might play out in tonight’s debate, consider that all the candidates who aren’t Mitt Romney will probably treat Cain with kid gloves. Why? If Cain's campaign collapses, they will all want his supporters. And if you go too hard, you risk alienating them. Bottom line: Attacking Cain tonight on this issue, if you are another GOP candidate, comes with more risk than reward.Another dynamic to watch: Both Huntsman and Perry are in desperation mode. What do they do tonight?

*** The skinny: Tonight’s debate -- sponsored by CNBC and the Michigan Republican Party -- begins at 8:00 pm ET from the campus of Oakland University here in Rochester, MI (just outside of Detroit). It’s moderated by CNBC’s John Harwood and Maria Bartiromo, and it will feature questions from CNBC’s Jim Cramer, Steve Liesman, Rick Santelli, and Sharon Epperson. The eight candidates who are participating: Bachmann, Cain, Gingrich, Huntsman, Paul, Perry, Romney, and Santorum.

*** Another Perry ad in Iowa: Rick Perry (as first reported by Politico) is up with another positive biographical TV ad in Iowa. As we noted yesterday from our NBC/WSJ poll, Perry is continuing to lose support nationally. Do these ads begin to help his numbers in the Hawkeye State?

*** Super PACs hit the airwaves: Meanwhile, the GOP group Crossroads GPS says it’s airing a new TV ad (at a buy of $2.6 million) that hits President Obama in Colorado, Florida, North Carolina, Ohio, and Pennsylvania. And the Dem group Priorities USA is up with an ad criticizing GOP cuts to Pell grants.

*** On the 2012 trail: Before tonight’s debate, New Jersey Gov. Chris Christie campaigns for Romney in New Hampshire, and Buddy Roemer also visits the Granite State.

*** Wednesday’s “Daily Rundown” line-up (live from the debate site in Michigan): CNBC's Rick Santelli, Sharon Epperson, and Steve Liesman on what they're expecting when they question the candidates at tonight's debate… Rep. Candice Miller (R-MI) on tonight's debate (just over the line from her district) and why she's backing Perry… Romney Campaign Senior Adviser Eric Fehrnstom… Democratic strategist Debbie Dingell… One of us (!!!) on Cain's non-accusation-related trouble spots... And NBC's Mike Isikoff on the politics of sexual accusations.